Busted a nice CPU PSU testing LED strip, question about potential fix

[Zekromtor]

This won't be a fix that is worth the time, I realize, but I'm curious. I have a relatively new model PSU that I broke by overloading the 12v- circuit using it to power an LED strip that wanted to pull 5 amps. That circuit is only good to .8 amps, unfortunately, I should have used the 12v+ circuit (which I did with another PSU successfully). My question to the more electronically experienced: what do you think I blew doing this, and do you think it can be replaced? The main fuse is still fine (as expected, certainly didn't pull enough to bust that).

[vvp]

Hard to tell. Probably on the final rectifier stage or the final filtering inductor for -12V output is fried. Or maybe the -12V lead on the PCB. Try to look inside and follow the -12V conductor from the output back to the secondary winding of the main transformer. Look whether something is not scorched there.
The point is that -12V secondary winding is shared with +12V secondary winding. So it should withstand high currents without a problem from the mains to the end of secondary winding.

[Zekromtor]

Well, I ended up taking it apart, but I could see nothing abnormal inside. After I put it back together I decided to try it one more time, and it started running again.

I'm still curious as to what kind of safety mechanism must have been tripped. I had tried completely powering it off, disconnecting from power, and reconnecting it with no joy. When I took it apart I discharged the capacitor for safety, so maybe that allowed it to reset that mechanism?

[vvp]

PC power sources use overload protection or reset-able fuses. So if the overload is not too severe or on an unexpected place then the fuse/protection has enough time to shut it down without permanent damage. The fuse/protection resets in about 1 - 10 minutes after the power source is disconnected or switched off. So if your PC power source stops to work then switch it of for about 10-15 minutes and try again. If it still does not work then it is time to took it apart and check what failed.